<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8" />
		<title>4.复习几个常见的方法</title>
	</head>
	<body>
		<script type="text/javascript">
			let str = 'abcde'

			// //判断字符串中，是否包含指定字符
			let result = str.indexOf('')
			console.log(result)

			//变量提升问题
			// console.log(a);
			// let a = 1;
			
			//边缘性问题
			/* let obj = {
				name:'tom',
				age:18
			}
			console.log(obj.name)
			console.log(obj['age'])
			console.log(name) */

		</script>
	</body>
</html>